Method of automatic regulation of the supply of oxidizing agents, such as nitric acidnitrate solution, or others in the manufacture of sulphuric acid



are 11 1924. 31,486,757

' E. JENSEN METHOD OF AUTOMATIC REGULATION OF THE SUPPLY OF OXIDIZING AGENTS,

SUCH AS NITRIC ACID, NITRATE SOLUTION, OR OTHERS IN THE MANUFACTURE OF SULPHURIC ACID Filed May 51, 1923 fin suppli ing sible and that the supply corresponds to the d supposition that "H7 Stadhouderslaan, The

provements relatin taining the lowest checked, and

"c ones in the quantities of msr .nmsnn, or rm: HAGUE, News.

EDD 01! AUTOMATIC REGULATIOIll OF THE SUPPLY -GI" OXIDIZING AGENTS, SUCH as mrmc ACID, mmarn SOLUTION, OR cranes in THE nmmmacroan or sunrn omc acm.

To all whom it may concern.

s it known'that T, ERNST JENSEN, a su bject of the King of Denmark, residing at Hague, Nethers,' have invented new and useful Imto the method of automatic regulation the supply of OXldlZdIl agents, such as nitric acid, nitrate solution,

or others in the manufacture of sul huric I acid; and I do hereby to be a full, clear, 0 the same.

e manufacture of chamber 5 stems, tower. systems and the like requires tli at nitric acid or other nitrogenoxldes ielding substance be continuous] in quantity corresponding to the nitrogen oxides incurred in the declarethe fol owin and exact descriptlon sulphuric acid in loss of process; 7

One of the principal conditions for obossible consum tion of, oxidizing agent is t lat the supply 0 oxidizagents takes place as regularly as-p The regulation of this supply has hitherto operator of the plant by adjusting a cock, and" experience shows that this method is rather defectirej Experiments have been the regulation of the supply 0 oxidizing agentis effected by means of an electrically controlled cock in such a manner that as the temperature-in the first chamber increases the supply of oxidizing agents is asthe temperature in the chamr decreases the supply ofoxidizing agentis increased. This method was based upon the in a normal chamber plant the supply of SO plus SC) is nearly constant, and that a decreasing temperature is due to lack of oxidizing-agents. This supood in t connumerous ot er conditions frequently cause SO plus 550 E and therefore a introduction of oxidizing coped to the chambers .aia 0f the Application filed May 31,

g gives a result opposite to y of sulphuric acid there I the gases in the last chamber,

that giving the been effected by the I in ordinary chamber plants it chamber to increase. the uantlty of the oxidizing agent re- 1923. Serial in. 642,682.

g creased supply of the oxidizing agent, al-

though th e supply should hare been reduced. n th is case then the automatic regulation What is aimed at. ccording to the present invention it has been endeavoured to regulate the admission oxidizing agents according to the following principles:

In chamber plants for the manufacture will always exist correspondin to the most favourable conditions for the sulphuric acid i'forming processes, namely n a given plant in regular working this difference of tem erature is nearly constant.

t is updri this 0 servation that the principle of the regulation of the admission of of temperature varies according to the conof the various plants, but hes between en in ordinary working a constant current of the oxidizing agent is supplied, corresponding to the quantity of the oxidizing agent lost during the same time, experience shows that the greatest economy 1s obtained, and'that the said difference of temperature is almost constant.

the admission of oxidizing agent is inchange of chambers occurs, fi'erence of temperature between the first and the last If on other hand mg a diminution o 'fi'erence of temperature in all the trated. Thusother temperature sensitive means, such as air filled 'containeiior air thermometers, can be used'for thepurpose and the apparatus shown only represents one of the means we have used for carrying out the invention in practice.

The chamber plant shown consists of three chambers 1, 2 and 3,. a Glover tower a and Gay-Lussac towers 5, 5. 6 is a container for nitrate solution or other oxidizing substance from which the liquid is admitted to the first chamber 1 through an electrically controlled valve-7, the stem. 8

of which is connected with the iron core 9 .19, contact piece 20, wire 26, coil of-rela of a solenoid -10 which iron core is suspended by a spring 11 as indicated.

In the chambers 1 and 3 electrical resistances, 12 and 13 respectively, whichare sensitive to variations of their temperatures are inserted and they are connected with, two proportionate resistances 14 and 15 and a galvanomcter 16 and a measuring cell 17 to form. a Wheatstone bridge, so that the difference between the temperatures of the first and the last chamber can be measured by means of the galvanometer. The zero position of the galvanometer hand 19 corresponds to the difference of temperature which is to be maintained between the said first and last chambers. On the scale of the galvanometer is placed a maximum contact piece 20 and a minimum contact piece 21, so that the hand of the galvanometer, when touching one of these contacts. closes or interrupts thecurrent from a local'battery 22. This current controls the valve 7 which controls the supply of oxidizing agents by means of two relays 23 and 24 in the following manner.

When the difference of temperature at the .places of measurement has assumed its maximum, the galvanometers hand 19 will make contact with the contact piece 20. Hereby a 1 local circuit is closed as follows: from one pole of the battery 22 through wire 25, hand 24, wires 27 and 28 to the other pole of the battery 22. The current causes the relay 24 to make connection between the contact elements 29 and 30, and thereby is closed the following controlling circuit: from one pole of the battery 22 through wires 25 and 31, contact elements 32 and 33 of the relay 23, wire 34, contact elements 29 and 30, wire 35, coil of solenoid 10, wires. 36, 27 and 28 to the other pole of the battery. The solenoid 10 thereby. eiiectsthe closing of the valve 7, and admission of the, oxidizingagent is stopped.

As described above, a change of tern erature will now take place in all the 0 amhere, causing a decreasing difierenceof temperature between the places of measurement where the resistances 12 and 13 are located, I The deviation of the hand 19 now de creases, and it will pass through the zero position and reach the minimum position, where'it will make contact with the mini mum contact piece 21. Hereby the following circuit is closed; from one pole of battery 22 through wire 25, hand 19, contact piece 21, wire 37, coil of relay 23, wires 38 and 28 to the other pole of battery 22. The current causes the relay 23 to interrupt the connection between the contact elements 32 and 33 and the controlling circuitthrough the solenoid 10 is interrupted. The valve 7 is now opened again and the admission of oxidizing agent is started again. The temperature in all the chambers will then again e subject to a change, and the difi'erence of temperaturebetween the" measuring places is increased. Theoxidizing agent is admitted constantly, until greater deviations from the normal temperature difi'erence between the first and last chamber again occur. a

The effecting of the controlling described above can be inversed if simultaneously the controlling of the valve by the solenoid is altered in such a manner that the closing of the controllin circuit causes that the valve is opened, an vice verse. I

Ifdesired, the galvanometer can be adapt ed for recording of these fluctuations oi the difi'erence of temperature, thus effecting a survey of the working or the plant by day and by night,

In acertain plant the normal difference o temperture between the first and last cham her is for instance 40 and the zero position of the glavanometers hand is adjusted to that point by suitable adjustment of the resistances. The maximum and minimum contact pieces are for instance adjusted at 41 and 39. The controlof the supply of the oxidizing agent will then take place as descrlbed above, and the apparatus will auto.- matically endeavour to keep the difierence between the temperature .of the first and y last chamber at about l0 with a deviation of one degree perature."

The galvanometer can be adjusted with the zero position corresponding to another difference of temperature, and the maximumand minimum-contact pieces can be adjudabove and below this tern Mil eel so as to permit greater or smaller devise" lions from ehenormal (iifiereuce than indicsled abuse.

The escrilwi controlling apparatus can connected with and control one or more sppeistus sclxniciing the oxidizing ugente, for instance in such u way that these upperaius are controlled simultaneously on one after the other. Furthermore the controlling apparatus can be connected will: the admission device in such amanner iliut the iregulaiion of the supply only lashes place for part of the total supply, while the other pars is admitted by means of a separate u 3155 pumtus not auto .usicully controlled. mi nully the controlling system described can be adapted so as to control two more udmission apparatus for ewo or more first chambers, so that any of the u issiou upil puratus are controlled according as the difference of temperature existing between the first and the last chumber in question Having thus fully described my inveuiion I claim as new and desire to secure by Letters Patent: 1. Method of controlling the admission of oxidizing agents in the manufacture of sulphuric acid, characterized by the admission of the oxidising agent being made deperature of the gases when when leaving the the plant. I

' 2. Method of controlling the admission 0f 0Xl(llZlIlg agents in the manufacture of dizing a gent being" checked when the difi'erence oecween fiche entrance and the exit temperatures in. line 40 chambers of reaction of the plant has in creased to a, fixed value and is started again be lie full extent when the snici iliileeeuce of 'fiempemure has decreased to u value c 3. in the recess like inenufeelucs ui? sulphuric ucicl by the chamber omcess the slap which consists in muiuieimug u sub stanisiuliy constant, lemperutuz-e g riclienis in t e resacfizing gases by verging she supply of 'dizing gases be the clmmhens.

i. In the recess fee the menufsciiure ell sulphuric acid by the chamber process this siepswhich consist in determining the clifi'erence in temperatures of the gases in the first endthe lust chambers of the system most favorable to the pmeess, iucreue' u the supply of oxidizing ugene as the difference between the temperatures of the us% in the firsiand last cliambei's of the swim falls beloiw said determined tempeunure difierence, and decreasing the supply of oxidizing agent as the (lifierence between the temperatures of the gases in the first aiufi the last chambers of the system rises above said determined temperature difference ence is substantially In the process for the manufacture of sulphuric acid by ihe chamber process the steps comprising iiicreasing the oxidizing agent when the fall in tempera,-

maintained.

less and decreasing the supply agent when the fallin temperature of Elie gases in the system becomes greater than u predetermined value.

in testimony whereof I have affixed my signature in presence of two witnemes.

ERNST JENSEN, Witnesses:

-W. UDEENHALK, W. Lemmas.

us I n 0 7 whereby said determined temperature difier- 

